linux-kernel - [tip: x86/core] x86/usercopy_32: Simplify __copy_user_intel

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 13 Dec 2021 09:50:11 -0000
From:   "tip-bot2 for Peter Zijlstra" <tip-bot2@...utronix.de>
To:     linux-tip-commits@...r.kernel.org
Cc:     "Peter Zijlstra (Intel)" <peterz@...radead.org>,
        Josh Poimboeuf <jpoimboe@...hat.com>, x86@...nel.org,
        linux-kernel@...r.kernel.org
Subject: [tip: x86/core] x86/usercopy_32: Simplify __copy_user_intel_nocache()

The following commit has been merged into the x86/core branch of tip:

Commit-ID:     13e4bf1bddcb65dd028aaa492789e8d61efaafa1
Gitweb:        https://git.kernel.org/tip/13e4bf1bddcb65dd028aaa492789e8d61efaafa1
Author:        Peter Zijlstra <peterz@...radead.org>
AuthorDate:    Wed, 10 Nov 2021 11:01:21 +01:00
Committer:     Peter Zijlstra <peterz@...radead.org>
CommitterDate: Sat, 11 Dec 2021 09:09:50 +01:00

x86/usercopy_32: Simplify __copy_user_intel_nocache()

Have an exception jump to a .fixup to only immediately jump out is
daft, jump to the right place in one go.

Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@...hat.com>
Link: https://lore.kernel.org/r/20211110101326.021517780@infradead.org
---
 arch/x86/lib/usercopy_32.c | 40 ++++++++++++++++++-------------------
 1 file changed, 20 insertions(+), 20 deletions(-)

diff --git a/arch/x86/lib/usercopy_32.c b/arch/x86/lib/usercopy_32.c
index 962006b..1eb1506 100644
--- a/arch/x86/lib/usercopy_32.c
+++ b/arch/x86/lib/usercopy_32.c
@@ -256,28 +256,28 @@ static unsigned long __copy_user_intel_nocache(void *to,
 	       "8:\n"
 	       ".section .fixup,\"ax\"\n"
 	       "9:      lea 0(%%eax,%0,4),%0\n"
-	       "16:     jmp 8b\n"
+	       "        jmp 8b\n"
 	       ".previous\n"
-	       _ASM_EXTABLE_UA(0b, 16b)
-	       _ASM_EXTABLE_UA(1b, 16b)
-	       _ASM_EXTABLE_UA(2b, 16b)
-	       _ASM_EXTABLE_UA(21b, 16b)
-	       _ASM_EXTABLE_UA(3b, 16b)
-	       _ASM_EXTABLE_UA(31b, 16b)
-	       _ASM_EXTABLE_UA(4b, 16b)
-	       _ASM_EXTABLE_UA(41b, 16b)
-	       _ASM_EXTABLE_UA(10b, 16b)
-	       _ASM_EXTABLE_UA(51b, 16b)
-	       _ASM_EXTABLE_UA(11b, 16b)
-	       _ASM_EXTABLE_UA(61b, 16b)
-	       _ASM_EXTABLE_UA(12b, 16b)
-	       _ASM_EXTABLE_UA(71b, 16b)
-	       _ASM_EXTABLE_UA(13b, 16b)
-	       _ASM_EXTABLE_UA(81b, 16b)
-	       _ASM_EXTABLE_UA(14b, 16b)
-	       _ASM_EXTABLE_UA(91b, 16b)
+	       _ASM_EXTABLE_UA(0b, 8b)
+	       _ASM_EXTABLE_UA(1b, 8b)
+	       _ASM_EXTABLE_UA(2b, 8b)
+	       _ASM_EXTABLE_UA(21b, 8b)
+	       _ASM_EXTABLE_UA(3b, 8b)
+	       _ASM_EXTABLE_UA(31b, 8b)
+	       _ASM_EXTABLE_UA(4b, 8b)
+	       _ASM_EXTABLE_UA(41b, 8b)
+	       _ASM_EXTABLE_UA(10b, 8b)
+	       _ASM_EXTABLE_UA(51b, 8b)
+	       _ASM_EXTABLE_UA(11b, 8b)
+	       _ASM_EXTABLE_UA(61b, 8b)
+	       _ASM_EXTABLE_UA(12b, 8b)
+	       _ASM_EXTABLE_UA(71b, 8b)
+	       _ASM_EXTABLE_UA(13b, 8b)
+	       _ASM_EXTABLE_UA(81b, 8b)
+	       _ASM_EXTABLE_UA(14b, 8b)
+	       _ASM_EXTABLE_UA(91b, 8b)
 	       _ASM_EXTABLE_UA(6b, 9b)
-	       _ASM_EXTABLE_UA(7b, 16b)
+	       _ASM_EXTABLE_UA(7b, 8b)
 	       : "=&c"(size), "=&D" (d0), "=&S" (d1)
 	       :  "1"(to), "2"(from), "0"(size)
 	       : "eax", "edx", "memory");